Taboo: A Mage's Guide to Fucking Up
by NecroPriestess
Summary: There was only two rules. Don't fuck the skeleton, and in the case that you do, do no become his sex slave. Frisk somehow managed to do both within the first ten minutes of meeting him. Underfell AU.


**A/N:**

 **Title: Taboo**

 **Summary: There were only two rules. Don't fuck the skeleton, and in the case that you did, don't become his sex slave. Frisk somehow managed to break both in the first ten minutes of meeting him.**

 **Warnings: Sex. Very rough sex. Slavery. Seriously rough sex. Cursing. Extremely rough sex. Blood. Crazy rough sex. Did I mention sex?**

* * *

Frisk never claimed to be the smartest mage alive. Sure, she knew how to turn a spell or two when she really had to, but aside from that she was average. Her familiar was basically a slime person, her spell book was written in chicken scratch, and she had a bad habit of beheading her imps when she summoned them. All solid proof that she should probably be the last person alive to go check to make sure the barrier within Mt. Ebbot was still standing. She shifted in front of the Grand Master; hands folded neatly in front of her and face set in a neutral expression. The old man was bent over a map, his back hunched in an uncomfortable position, and his arms shaking to keep him up. Frisk briefly wondered if it was a good idea to spook him, just to see if he would fall face first into the bowl of kale soup sitting on the map.

Her thoughts were quickly banished as the man looked up at her, brown eyes narrowed as he looked her over. "Frisk Alice Drake," His voice was gruff and always made Frisk feel like she was in trouble, even when he was complimenting her. "the other masters of our order have elected you to journey down to Mt. Ebbot, and ensure the barrier is still burning strong over the monsters. Are you aware of this?"

And here comes all the legal mumbo jumbo. Technically speaking, she could sue the entire Mage Order if she wasn't properly briefed about the dangers her mission would have. Now, most human lawyers didn't believe in magic, but even mages doubled as lawyers. Lying, sneaky, and despicable mages you didn't invite to parties, but still good lawyers.

"Yes, Sir."

"And do you know that the monsters under the old mountain will have every intention to kill you?"

"Yes, Sir."

"Maim you?" She repeated her affirmative, her voice sliding into a dull monotone. He went through a whole dictionary full of things that could happen if she didn't keep her eyes open. Some being theft, experimentation, harassment, being burnt alive, choked, raped, and clothes irreversibly damaged. The old man rubbed at his eyes with his thick fingers, kneading the dark skin like some sort of cookie dough. "And you are aware that if you are to die then your soul will not be given the proper rites of burial?"

"Yes, Sir-"

"Good." Frisk flinched as he slammed his hand down, the sound echoing off the high vaulted ceiling of the library. "Then you're free to go, I'll have William go over the paperwork one more time before I give you the teleportation spell." The man gave a short sigh. "You may want to put all of your affairs in order; it's not guaranteed that you'll survive this ordeal, so there may be things that you want to ensure for your…cat." Frisk fought the urge to roll her eyes, now the old man was being an ass. "Any questions?"

Frisk shook her head, without another word the man waved her away as he sank into a stiff looking rolling chair. The young mage hurried out of the library and into the main hall of the Order Estate, her boots clacking against the polished hardwood as she went to the dorms. A few of the lingering mages openly stared at her, a few whispered behind their hands and books, while some gave her pitying glances. The open staring part was the one that was the most prominent, she guessed that might be a good thing, maybe that meant only ninety percent of her fellow mages thought she would die, not all one hundred percent.

She turned a sharp corner and went down the stairs, they led to the outside path that meandered all the way to the dorms. Most mages didn't live in the dorms, instead they lived in the towns or cities they were assigned to look over. Mages who were not guardians lived on the estate, and spent their time learning the craft so they could become teachers for the next generation. Frisk would have sold her left kidney to stay on the estate, there was no bills or rent, just study time that had to be docked in. And since her place was a nice one bedroom/one bath with enough space to host half decent parties, she wasn't about to complain.

Frisk fished her keys out of the pocket of her skirt as she went through the dorm gate. Seeing as how it was early morning, most of the dorm dwellers were in classes or studying. This allowed her to hurry to her room without getting stared at. She went up the stairs of the first apartment complex and went down the row of doors until she made it to the sixth one. She quickly unlocked it before going into her comfy apartment. The fan was on giving her a nice breeze, and stirred her air around enough to allow the scent of her orange candles to circulate all the way to the living room. The girl kicked her shoes off and went to the kitchen, running a hand through her sleak brown hair. "What to eat?"

A meow caught her attention and she knelt down in front of her cat. He was small, barely the size of a load of bread, and an ugly off gray color. She found him on the street a few months ago, he was a good replacement for her old cat, and didn't scratch her half as much. She bet his head, and he gave a content purr as he leaned into her hand, his bell chiming with the movement. She gave a small smile before standing up and cleaning her hands, before going to her refrigerator to find food. She opened up her refrigerator, and drummed her fingers against the metal as she stared at the food. Most of it was pizza, she had an obsession with the stuff, it was the main reason she wasn't as thin as she'd like to be. She reached a hand in and grabbed a slice of three meat pizza and took a bite out of it before shutting the fridge.

There was a sharp tug on her soul, and her surroundings dimmed in coloras something red snaked out of her chest. It curled and bubbled, looking like some kind of mutant puss creature. If she wasn't so used to seeing this, she would have vomited up her food immediately. She watched in vague interest as the thing morphed into a gelatinous version of her, the only real difference being that it was thinner and had no noticeable eyes under the fringe of her bangs. The creature crossed her arms and 'stared' for a long moment. When she didn't get a reaction out of Frisk, she reached out and yanked on some of her dark locks.

"Hey!" Frisk swatted the hand away. "I know you can talk, use your words, I can't read brat language."

The thing growled and jabbed a finger at Frisk. "Why on earth did you accept it! You didn't say no, talk it over, anything!"

Frisk finished off the rest of her pizza and went to her small sink to wash her hands again. The thing behind her glared as she gathered her lemon soap into her hands, admiring the way it made them so soft. "It's really not my choice, you know that."

"Yeah, but you've got leverage!" She waved her hands around. "Look at me, I'm a determination class familiar, how many of those are running around this scrappy place?"

"Six?"

"Exactly!"

Frisk rinsed off her hands, the cold water made a chill run down her spine and she shuddered. The familiar behind her mirrored the action. "Some things are best this way, Risk. If if works out, then my body will be put with the rest of the 'Guardians of the Barrier', and I'll never have to pay taxes."

"And if you die?"

Frisk shut off the water and turned on her hell, most of her body weight pressed against the granite counter top. "Then I still won't have to pay taxes."

"...Your life is rather meaningless, isn't it?"

"Yup."

* * *

The next morning Frisk awoke to someone pounding at her door. The girl groaned and sat up in bed, her back popping after being straightened after so many hours. A quick glance at the window showed that it was much too early to wake her up. There was only a pinprick of light easing over the horizon, it was almost completely swallowed by the clouds mingling with the dark. Another hard knock at her door reminded Frisk of reality, forcing the girl to swing her legs over the side of the bed, and stumble to the door. She yanked open with all the irritation she felt, just to come face to face with a tall blonde. The young man smiled, ruining the image of his perfect face, with a few rotting teeth. "Hey, Fred..." She felt a tremor in her soul, and she had to squash down Rosa's desire to attack. "What're you doing here so early?"

The man held up a brown paper bag, something warm and smelling suspiciously maple syrup caught her attention. "I was told to get you ready, you'll be leaving in an hour for your pilgrimage."

"Oh." Frisk moved aside so he could come in. Like every other person in the entire world, he didn't take off his shoes and just strolled in, the act made Frisk shudder. She was going to have to find time to vacuum her floor before she left.

Fred sat on her love seat and opened up the bag, while Frisk took down two glass plates. "According to Mr. William, all of your documents are in order. The Grand Master has taken all of the precautions that are meant for teleportation as well, you'll just have to go and enact the spell when he gives you the inscription for it." Frisk watched him put two doughnuts on her plate, and a honey bun on his own. She muttered a thank you before taking a bite out of it. It was flakey, but had the perfect amount on glaze on either side. She hummed in approval, as she swallowed the bite. "Frisk, I think there's one more thing you ought to do before leaving."

All of Frisk's happiness died then. She half wondered if Fred was just geared that way, a person who was meant to stop any of the fun she had. "Yeah?"

Pink lit up his cheeks in a cute blush, Frisk almost wanted him to shut up so she could admire how cute he was. Another sharp tug at her soul squashed that thought, and she focused on his words instead. "We've been acquaintances for a long time now. I believe that it is time we go beyond that, and engage in something more."

"Uh...yeah" Frisk felt her own cheeks heating up, she's never been so thankful for her dark skin as she was at that moment. She didn't want to give the poor sap any hope that she was interested in him. "Fred, about that."

"It's okay." One of his large hands enclosed around her free smaller one. "I know that you're about to embark on a grand adventure, but I cannot leave this unsaid. I don't want any regrets in my life, and not saying this would be the biggest one." And of course the Bravery in him had to actually work. She wished he had another spark that wasn't so pesky, like Integrity, everyone with Integrity sparks knew when to back off. "I love you Frisk, and I have for a very long time. And I know this may be sudden, but I'd love it if you would possibly consider becoming my Eros spell partner."

"..." Well that wasn't what she was expecting. Eros spells were spells that used the act of sex as the ACT. They usually required one person to cast, and were so easy she wondered if he was being for real. Plenty of people used Eros spells as an excuse to have sex with someone out of their league, and while Frisk wasn't out of Fred's league...Well, she didn't want to be reminded about the fact that she didn't have any options other than the guy who was currently married.

"Well?" He squeezed her hand gently. "I know I'm a workaholic, but this is the best way for the both of us to bond. Working such spells would allow me to see you, and still work, isn't it perfect?"

No, it wasn't. She wondered if it would be rude to summon Risk to kick him out of the house. A tug on her soul basically gave her the answer, and Frisk had to quickly stand up as she fought her familiar from leaving her soul. "I uh, I really don't wanna think about this before I'm shipped off to die, you know?" She slammed a hand over her chest. "Can we postpone this?"

She didn't give him a chance to answer as she hurried out of her room and to her own. She really hoped he took it as rejection, or at least a cue for him to keep his Eros spells for himself, his blow up doll, and his wife.

* * *

There was no pomp and circumstance when a Barrier Gaurdian was sent off. The only people present was the Grand Master, the Spark Gaurdian, and the librarian. All three stared at her as she entered the room, a backpack firmly attached to her shoulders and a proper docile look on her face. The Grand Master gestured to the center of the room, a circle dictating where she would be do the spell was drawn into the floor in white chalk. "If you're prepared, go ahead and do the spell as per the instructions."

The Spark Gaurdian gave a short laugh, it sounded like a cat puking, befitting an old woman who looked like one. "You make it sound so easy, like turning a car on."

The Grand Master rolled his eyes, but didn't respond to the woman's teasing. "This spell can only be enacted again once, Frisk." He held up one long finger to make that fact hit home. "Just once, anything after that will just kill you, and that would be a damn shame after everything you're about to go through."

Frisk nodded as she carefully walked into the center of the circle, taking a ripped up envelope from the librarian as she passed her by. On it was the set of directions needed to make the spell actually worked, scribbled in yellow crayon, and no notes to help her. Just the Grand Masters ever lazy and uncaring style. She swallowed heavily as she pressed a hand to her chest. Ever so slowly a small red heart began to peek through her blue and purple sweater. When she first did this as a child, she thought it would hurt, but all it did was make her chest go numb and plunge everything into a monochrome world of black and white. She focused on the small thing as she held it between both of her hands, letting go all control over it.

As soon as she did, there was a loud crack and twelve shadowy holes opened up in the ground in a perfect circle around her. Imps were twisted creatures, they looked like something out of a cheap horror film, with their tentacles and dog like heads. Speaking of which, as expected they all fell off with a bloody splat. The heads clung to the bodies, attached only by chunks of muscles and splintered bone. The Spark Gaurdian laughed while the Grand Master shook his head, muttering something about getting a drink. Frisk grit her teeth, but didn't stop, they knew she sucked at magic, this really shouldn't have surprised them.

Seeing as how the imps hadn't left down into the chambers again, it looked like she could do the next part, ACT. An ACT was something that cemented the imps to this plane long enough so that their magic wouldn't cause a nuclear explosion. Seeing as how she summoned giga imps, it looked like the ACT of the day was going to be more mental than physical. She shut her eyes and tugged on her soul strings, gaining the attention of the imps who were holding them. She sent a warm feeling towards them, one that made her heart feel fuzzy and a sense of nostalgia take over. The giga imps clung firmly to her soul strings now, and when she opened her eyes, they looked more corporeal.

Now for the final block, Spark. Spark was the thing that all humans had, but only mages could actually use. Bravery, Determination, Integrity, Patience, Kindness, Perseverance, and Justice. Seeing as how Determination was the rarest put Frisk at a disadvantage, that was a type of spark the imps would want. If she wasn't careful, they would drag her soul and eat it while she was still alive. It was cool only in theory, not actual practice. Red bubbled out of her soul and onto the ground, instead of taking the shape of her familiar, it began the actual 'spell' process. The gunk stretched out to all of the imps, and easily eased into their own souls. Frisk whined and had to curl her toes to keep focused. She felt stretched, like someone had taken a rolling pin and gotten to work on her flab, leaving her behind in twenty different directions.

Slowly the room began to hum as the giga imps responded to the spell, and began weaving their own. Swirls appeared in the air, an inky black that stretched itself up like a decaying spider web. Slowly the threads began to connect until it created a barrier of sorts. Frisk shifted nervously, and looked back o the impressive Grand Master. "You don't have a time limit Frisk, and we'll know if you died. Just try to stay alive, alright?"

That was the last thing she heard before the ground under her crumbled, and she fell into a pit of nothingness.


End file.
